Problem: $\dfrac{9}{2} - \dfrac{3}{2} = {?}$
Answer: $ = {\dfrac{9 \times 1}{2 \times 1}} - {\dfrac{3 \times 1}{2 \times 1}} $ $ = {\dfrac{9}{2}} - {\dfrac{3}{2}} $ $ = \dfrac{{9} - {3}}{2} $ $ = \dfrac{6}{2}$